Ankle Sprain

Introduction

An ankle sprain is the most common ankle injury accounting for ~4% of all UK emergency department attendances. They involve at least one of the ankle ligaments, with injuries ranging from a small tear to a complete rupture of one or more ligaments.

 

​Presentation

  • Twisting injury of the ankle
  • Pain, swelling and bruising at the site of the affected ligaments
  • High ankle sprains will be more painful at the syndesmosis during external rotation of the ankle with the foot in a plantigrade position or squeezing the ankle at the level of the syndesmosis

 

Classification

​Ankle sprains are classified into either lateral, medial or high depending upon their location.

​Lateral ankle sprains are the most common sprain, occuring in 85%, of cases. The most commonly injured structure is the ATFL which usually results from inversion of the ankle whilst the foot is plantarflexed.​

Isolated medial ankle sprains are uncommon, as the deltoid ligament complex is the strongest of the ankle ligaments. These can occur in isolation or in combination with lateral ligament injures. These injuries are discussed in more detail in another section. 

​High ankle sprains involves the anterior, posterior and transverse tibiofibular ligaments and the interosseous membrane i.e. the syndesmosis. The region of pain and tenderness is different and is located in the groove between the distal fibula and tibia, superior to the lateral malleolus.

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Grading

Sprains are graded from I to III with increasing severity.

Grade I - stretching of a ligament without any macroscopic tears

Grade II - partial tear of a ligament

Grade III - complete tear of a ligament

 

Assessment

Assessment is primarily clinical to identify the location of injury however radiological investigation is needed when the history of trauma is suspicious for a high energy injury, high ankle sprain, multiligament injury or when symptoms fail to settle after initial conservative measures.

It is important to not miss injuries which may mimic an ankle sprain such as a fracture or Achilles tendon rupture.

Further investigation may include plain radiographs and MRI.

 

Management

Several systematic reviews have highlighted a lack of quality evidence to aid clinical decision making, whether to mobilise or immobilise the joint, and, if immobilisation is chosen, which types of supports provide the best choice. However, a multicentre RCT by Lamb et al. (584 patients with acute sprains in 8 UK centres) reported that short period of immobilisation in a below-knee cast or Aircast splint resulted in faster recovery than if the patient is only given tubular compression bandage in the early stage after sprain, and promoted faster recovery of function at 3 months.

​In acute phase, elevation, ice and compression are helpful. After an initial period of rest and protected weightbearing , gradual rehabilitation starts as soon as pain and swelling improves. Emphasis is generally focussed on improving proprioception and dorsiflexion, as an inadequate recovery has been shown to lead to recurrent sprains.

​Several therapeutic interventions are tried to improve dorsiflexion including stretching, manual therapy, electrotherapy, hyperbaric oxygen therapy, ultrasound and exercises, and a combination of some or all of these interventions are effective.

​A systematic review by Gribble et al. concluded that a static-stretching intervention as part of a standardized home exercise program had the strongest effects on improvement of ankle dorsiflexion after acute sprains.​

Tightness in the gastrocnemius-soleus complex is not likely to be caused directly by acute ankle sprain but may develop as an adaptive response to immobilization and result from an abnormal gait pattern. The stretching intervention is believed to increase the flexibility before pain perception and allows the viscoelastic properties of musculo-tendinous junction to overcome the stretch reflex or increase the stretch tolerance.

​Ankle dorsiflexion is typically restricted by pain, spasm and swelling. Cryotherapy and electrotherapy often are incorporated to minimize pain, spasm and neural inhibition, and thereby allowing for earlier and more aggressive interventions that aim to restore normal function.

​Hyperbaric oxygen therapy is purported to cause vasoconstriction, facilitate reabsorption of extravascular fluid into the circulation, and accelerate debridement by increasing oxygen delivery to macrophages, thus assisting in controlling the amount of swelling.

Borromeo et al. reported small to moderate effect sizes for increases in ankle dorsiflexion after 1 dose of hyperbaric oxygen. Therefore, although associated with mostly favorable results, the improvement in ankle dorsiflexion after 1 dose of cryotherapy, electrotherapy, and hyperbaric oxygen may not be clinically relevant.

​Green et al. reported a small associated effect size for acute increase in ankle dorsiflexion after a RICE protocol in the control group, whereas Peer et al. reported negative effects for immediate improvement in ankle dorsiflexion after a RICE protocol in patients with acute ankle sprain.

​Sandoval et al. noted strong effect sizes after negative-polarity high-voltage pulsed stimulation (HVPS) with a standardized intervention program or the standardized intervention program alone.

​Selection of therapeutic interventions for improving ankle dorsiflexion after ankle sprains depends on multiple limiting factors to dorsiflexion. Hence it is important for a clinician to consider an approach to improve the dorsiflexion that may necessitate recognizing the key factors that limit ankle dorsiflexion.

​A systematic review has reported that most recovery occurs within the first 6 months after the sprain, and re-injury rates stabilise thereafter.

​For surgical management of acute and chronic instability, please read the page on Ankle Instability.

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References

  • Terada M, Pietrosimone BG, Gribble PA. Therapeutic Interventions for Increasing Ankle Dorsiflexion After Ankle Sprain: A Systematic Review. Journal of Athletic Training. 2013;48(5):696-709. doi:10.4085/1062-6050-48.4.11.

  • Baumhauer JF, Alosa DM, Renstrom AF, Trevino S, Beynnon B. A prospective study of ankle injury risk factors. Am J Sports Med. 1995;23(5):564–570

  • Denegar CR, Miller SJ., III Can chronic ankle instability be prevented? Rethinking management of lateral ankle sprains. J Athl Train. 2002;37(4):430–435.

  • Green T, Refshauge K, Crosbie J, Adams R. A randomized controlled trial of a passive accessory joint mobilization on acute ankle inversion sprains. Phys Ther. 2001;81(4):984–994.

  • Sandoval MC, Ramirez C, Camargo DM, Salvini TF. Effect of high-voltage pulsed current plus conventional treatment on acute ankle sprain. Rev Bras Fisioter. 2010;14(3):193–199.

  • Gribble PA, Guskiewicz KM, Prentice WE, Shields EW. Effects of static and hold-relax stretching on hamstring range of motion using the FlexAbility LE1000. J Sport Rehabil. 1999;8(3):195–208.

  • Verhagen RA, de Keizer G, van Dijk CN. Long-term follow-up of inversion trauma of the ankle. Arch Orthop Trauma Surg 1995; 114: 92–96.

  • S E Lamb, J L Marsh, J L Hutton, R Nakash, M W Cooke, on behalf of The Collaborative Ankle Support Trial (CAST Group); Mechanical supports for acute, severe ankle sprain: a pragmatic, multicentre, randomised controlled trial, Lancet 2009; 373: 575–81